将我国地势、地形特点对我国的影响连线:
被誉为“东方医学巨典”的是( )
例题:求代数式y2+4y+8的最小值.
解:y2+4y+8=y2+4y+4+4=(y+2)2+4
∵(y+2)2≥0
∴(y+2)2+4≥4
∴y2+4y+8的最小值是4.
-- Many students don't know what to stress and become worried.
-- I think they'd better ask their teachers for help.